This invention relates to spectacles used for correcting age-related or non-age-related farsightedness.
Ordinary spectacles comprise metal lens frames coupled together by a bridge at their upper portions, nose pads mounted to opposed portions of the lens frames or the bridge, and temples mounted to the outer ends of the lens frames through hinges so as to be folded into juxtaposition with the lenses fitted in the respective lens frames.
Such spectacles include those for nearsightedness, age-related and non-age-related farsightedness and astigmia. Spectacles for age-related and non-age-related farsightedness are used by farsighted people e.g. to read and write small letters. Since farsighted people can see things spaced apart from them, spectacles are usually not needed while, for example, they are walking. Thus, it is desired that such spectacles be as lightweight as possible, foldable neatly and convenient to carry.
The narrower the vertical width of spectacles, the more neatly they are foldable. There are already known spectacles including glass or plastic lenses having a vertical width of mere 2-3 cm and mounted on equally narrow lens frames.
Such conventional age-related or non-age-related farsighted spectacles have nose pads made from synthetic resin and arranged spaced apart a predetermined distance from the lens frames so as to come right over the eye. The nose pads usually engage the constricted portion of the nose. Thus it is impossible to put on two spectacles having such nose pads at the same time. For example, it is impossible to put on age-related or non-age-related farsighted spectacles simultaneously with nearsighted or astigmatic spectacles.
Conventional, easy-to-carry spectacles include neatly foldable spectacles having narrow lens frames. But since this type of spectacles have conventional nose pads arranged in the shape of , two of them cannot be put on simultaneously. Also, since the lens frames are made of metal, the entire spectacles are not lightweight enough.
In order to reduce the weight of spectacles, a synthetic resin, which is usually lower in specific weight than metals, should be used for as many parts of the spectacles as possible. But an easily moldable synthetic resin is usually soft and thus can be damaged very easily. Thus, plastic lenses formed by molding such a synthetic resin will be damaged easily by e.g. coming into contact with a hard object.
A first object of this invention is to provide spectacles which can be put on together with other ordinary spectacles to correct, among others, age-related or non-age-related farsightedness, and which are extremely lightweight, compact and easy to carry.
A second object of this invention is to provide spectacles made from an easily moldable synthetic resin and having means that prevent the lens surfaces from being rubbed and getting damaged by a hard object even when the spectacles are placed on such a hard object with the lens faces down.